The command line (or terminal) is a faster and more powerful way to maneuver your operating system than by using a GUI (graphical user interface), such as Windows Explorer or Mac Finder.

Use special keywords to do everything you can with a GUI and more.

Get-Service | Where-Object {$_.Status –eq “Running”}

OSX (Mac) and Linux operating systems are both based on Unix and share many of the same terminal commands.

However, Powershell has adopted aliases that mimic the most common Unix commands.

Windows has an entirely different kernel (base) and has traditionally had its own command-line syntax for MS-DOS and command prompt.

Powershell ships with all modern Windows systems (since Windows 7) and is a superior shell to command prompt. It compares favorably with Unix-based shells (such as bash).

The commands we will learn in Powershell are mostly Unix-like aliases for "cmdlets" that do things like change directories, manipulate files, and so forth.

You can write really powerful scripts with Powershell, which is built on the .NET platform. We will not cover that in this course. 

We will use the terminal to:

C:\

Program Files

Users

colt

...

Files and directories have absolute paths based on the root, where each additional level down adds a "\".

C:\Users\colt

The absolute path for "Colt" is:                   

The green directory below is a special directory called "home", which is also known as "~". This is the default directory upon opening your terminal.

C:\

Program Files

Users

colt ~

...

The cmdlet "pwd" (print working directory) will tell you the full absolute path of where you're at!

C:\

Program Files

Users

Colt ~

...

stuff

pwd

Path
----
C:\Users\colt\stuff

The command "cd" ( "change directory") followed by the absolute path of the folder will navigate you directly there.

C:\

Program Files

Users

colt ~

...

stuff

pwd

cd C:\Users

pwd

C:\Users

Path
----
C:\Users\colt\stuff

The dot "." stands for current directory, and dot-dot ".." stands for parent directory. This allows for relative navigation:

C:\

Program Files

Users

colt ~

...

stuff

pwd

cd ..

pwd

Path
----
C:\Users\colt\stuff

C:\Users\colt

The keyword "ls" will "list" the contents of a directory.

    Directory: C:\Users\colt

Mode                LastWriteTime         Length Name
----                -------------         ------ ----
d-----       12/28/2017   3:31 PM                .config
d-r---         1/5/2018   9:26 PM                Contacts
d-r---        1/10/2018   9:55 PM                Desktop
d-r---         1/5/2018   9:26 PM                Documents
d-r---         1/5/2018   9:26 PM                Downloads
d-r---         1/5/2018   9:26 PM                Favorites
d-r---        1/21/2018   3:03 PM                Google Drive
d-----         2/7/2017   3:49 PM                Intel
d-r---        1/18/2018  11:01 PM                Links
d-r---         1/5/2018   9:26 PM                Music
dar---        1/21/2018   3:03 PM                OneDrive
d-r---         1/5/2018   9:26 PM                Pictures
d-----       12/28/2017   3:21 PM                projects
d-r---         1/5/2018   9:26 PM                Saved Games
d-r---         1/5/2018   9:26 PM                Searches
d-----        1/21/2018   3:31 PM                stuff
d-r---        1/21/2018   3:03 PM                Videos

ls

The command "mkdir" ("make directory") followed by the name of the new directory will create a new child directory inside the current directory.

colt ~

stuff

colt ~

echo $null >> favs.txt

stuff

ls

    Directory: C:\Users\colt\stuff\catpics

Mode                LastWriteTime         Length Name
----                -------------         ------ ----
-a----        1/21/2018   5:28 PM              2 favs.txt

In Powershell, we can create files by putting empty content in them using the echo cmdlet.

Files can be moved or renamed using the "mv" (" move") keyword, which takes two arguments: the source and the destination.

Colt ~

mv favs.txt GOAT.txt

stuff

ls

mv GOAT.txt ..

cd ..

ls

Mode                LastWriteTime         Length Name
----                -------------         ------ ----
d-----        1/21/2018   5:33 PM                catpics
-a----        1/21/2018   5:28 PM              2 GOAT.txt

Files can be deleted using the "rm" ("remove") keyword.

Colt ~

stuff

rm GOAT.txt

ls

Mode                LastWriteTime         Length Name
----                -------------         ------ ----
d-----        1/21/2018   5:33 PM                catpics

Directories can be deleted using the "rm" keyword, with the added option "-r" ("recursive"). You can also add the "-fo" ("force") to prevent warnings.

Colt ~

ls

stuff

catpics

rm -r -fo catpics

ls

Warning: "rm -r fo" is a dangerous command! Be extremely careful what folder you pass to it because you will never get it back.

• OS file structure is hierarchical, tree-based

• Navigate using these commands:
  • cd "change directory"
  • pwd "print working directory"
  • ls "list contents"

• Remember these aliases:
  • C:\ is root directory
  • ~ is home
  • . is current
  • .. is parent

• Manipulate files with:
  • "mkdir" create directories
  • "echo $null >> filename" create files
  • "mv" move and rename
  • "rm" to remove files, "-r" to remove directories

For Powershell, we can use the Posh Git package here: https://github.com/dahlbyk/posh-git